In a first part of the study, 16 healthy male subjects will be included in each dose group and will receive test and reference product according to the cross-over design. After the end of the second period of each dose group (completion of both cross-over periods for each dose group) the pharmacodynamic and pharmacokinetic primary parameters will be calculated. The blinding will be temporarily broken by one statistician for the ad interim analysis of primary parameters that will be performed after conclusion of the treatment of 16 subjects for each dose group (results are not disclosed) with the aim to re-calculate the sample size and to conclude the study with the necessary and sufficient number of subjects for each dose regimen.